Build a new frame for your existing camper. Build a receiver into the back of it for a two bike mount. Then place a water or fuel storage system on the tongue for an adjustable weight bias to keep your tongue weight in line. Something as simple as 6 or 8 scepter/jerry can holder. Fill what you need when you need it. You can remove them to lift it off the ball when solo.

I like the thought. Was thinking more along the lines of what Corbet said- have a small shelf and receiver in back, then just shift cargo accordingly. But the dual water tank with self-adjusting pump does sound like a trick mod though. Though how much water do I really need to carry? 1 7 gallon jug seems to last us the weekend.

What would be even cooler would be more essential cargo attached to a movable tray, beneath the camper. 2 batteries, 2 propanes, jack, the spare tire, generator.. all on a movable slide supported by two tracks inside the frame rails, and a big lead screw that moves it as far forward as under the tongue deck (also for access), and as far back as right next to the axle. Probably 200 pounds of stuff you wanted to carry anyway. So instead of a pump with 2 tanks of water, it's just a motor turning a threaded shaft.. and you could have some type of auto/manual/off switch to control the thing.

edit: you could also do a second tray behind the axle, tied into the same motion. it hits the forward limit with the forward tray is under the deck, and its rear limit is against the back bumper, when the forward tray hits the axle. I wonder if 3' of movement is enough to get the adjustment you want, that's likely the limit here.

Though how much water do I really need to carry? 1 7 gallon jug seems to last us the weekend.

Water weighs 8 lbs per gallon or 64 lbs per cubic foot from memory. So you'll need to do the math on how much depending on distance from the axle to counter balance the bikes. If you drink all your ballast I'll refer you to this thread for the solution: http://www.risingsun4x4club.org/foru...t=17825&page=4

Dave will know where I'm going with this and can adjust his idea accordingly